No One May Ever Have This Knowledge Again: Letters to Mount Wilson Observatory 1915-1935″ is a fantastic, antiquated display of faded letters to astronomers from crackpots and simple people who have found the key to the secrets of Mars, the climate of the moon, and the holes in the sky. On loan from the observatory’s archives along with archaic scientific devices and irresistible old newsreel footage in a dramatically dim installation, it’s charming and almost beyond belief. “I hear that Einstein intends to visit your observatory in the near future,” writes a self-described clodhopper. “Hope he will, but he, with our help, should be careful not to go off on a tangent, for if a straight line is crooked, a curved line is straight.” The show touches down here thanks to the Museum of Jurassic Technology, David Wilson’s fictional but actual museum-as-a-work-of-art in Los Angeles. The artist-curator, who’s a master at blending fiction and fact, insists everything is real. This time, perhaps, we should believe him.